1. Field of the Invention
The invention relates to an injection pump for a common rail fuel injection system of an internal combustion engine, having a pump cylinder, disposed in a housing, having a piston oscillating in the pump cylinder, wherein the pressure of the fuel aspirated from a fuel inlet into the pump cylinder is increased by the piston, and having a quantity control valve, wherein the quantity control valve has a directly triggered control piston integrated with the housing, and the quantity control valve controls the pumping flow of the piston into an outlet or a high-pressure bore communicating with a common rail.
2. Description of the Prior Art
The injection pump known from German Published, Nonexamined Patent Application DE-OS 42 21 921 A1 is suitable for use in internal combustion engines with more than one cylinder only if it has a number of pump cylinders corresponding to the number of engine cylinders. With the number of pump cylinders, the production costs also rise.
In so-called common rail fuel injection systems, there is in principle the possibility of decoupling the number of engine cylinders from the number of pump cylinders in the high-pressure fuel pump. Because of the large temporary pumping quantity and the resultant peak torque value, and the previously unsolved problem of filling the pump cylinder in a very short time, until now single-die injection pumps were not used to supply fuel in common rails of internal combustion engines that have more than one cylinder.
The object of the invention is to provide a single-die injection pump for internal combustion engines with more than one cylinder that are equipped with a common rail fuel injection system.
The object is attained according to the invention by an injection pump for a common rail fuel injection system of an internal combustion engine, having a pump cylinder, disposed in a housing, having a piston oscillating in the pump cylinder, wherein the pressure of the fuel aspirated from a fuel inlet into the pump cylinder is increased by the piston, and having a quantity control valve, wherein the quantity control valve has a directly triggered control piston integrated with the housing, and the quantity control valve controls the pumping flow of the piston into an outlet or a high-pressure bore communicating with a common rail, and in which the piston oscillates at a frequency greater than or equal to half the crankshaft rpm of the engine. Alternatively, the single-die pump can also be controlled by an intake throttle valve.